Flexible photovoltaic modules having junction box supporting flaps

ABSTRACT

Provided are flexible photovoltaic modules having flaps for supporting junction boxes. Junction boxes are used for making electrical connections to photovoltaic cells sealed inside the modules. A flap may be formed by one or two flexible sealing sheets extending beyond the boundary of the photovoltaic cells. A junction box is attached to the front surface of the flap. In certain embodiments, a flap is formed by one sealing sheet, such as a back side sheet. Materials of the back side sheet may be different from materials of the front side sheet and be selected to ensure support to the junction box. Additional support to the junction box may be provided by extending one of its edges in between the two sealing sheets. This edge extension or other features may be used for mechanical protection of electrical leads extending between the junction box and photovoltaic cells.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of and claims priority to U.S.application Ser. No. 14/252,321, titled “FLEXIBLE PHOTOVOLTAIC MODULESHAVING JUNCTION BOX SUPPORTING FLAPS,” filed Apr. 14, 2014, which claimsthe benefit of priority to U.S. Provisional Application No. 61/811,461,titled “FLEXIBLE PHOTOVOLTAIC MODULES HAVING JUNCTION BOX SUPPORTINGFLAPS,” filed Apr. 12, 2013, all of which are incorporated herein byreference in their entireties and for all purposes.

BACKGROUND

Photovoltaic technology is being rapidly adopted to generate electricityfrom solar energy, both for local uses and for supplying power toelectrical grids. Photovoltaic systems may be implemented on vehicles,buildings, or as standalone photovoltaic arrays. Photovoltaic cells arethe basic units of such systems. One or more photovoltaic cells aretypically arranged into a photovoltaic module, which may be then used toform a photovoltaic array.

SUMMARY

Provided are flexible photovoltaic modules having flaps for supportingjunction boxes. Junction boxes are used for making electricalconnections to photovoltaic cells sealed inside the modules. A flap maybe formed by one or two flexible sealing sheets extending beyond theboundary of the photovoltaic cells. A junction box is attached to thefront surface of the flap. In certain embodiments, a flap is formed byone sealing sheet, such as a back side sheet. Materials of the back sidesheet may be different from materials of the front side sheet and cansupport to the junction box. Additional support to the junction box maybe provided by extending one of its edges in between the two sealingsheets. This edge extension or other features may be used for mechanicalprotection of electrical leads extending between the junction box andphotovoltaic cells.

These and other embodiments are described further below with referenceto the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are top and side schematic views of a flexiblephotovoltaic module having a flap supporting a junction box, inaccordance with certain embodiments.

FIG. 1C is an expanded side schematic view of a module portionillustrating various features of a flap and sealed space of a flexiblephotovoltaic module, in accordance with certain embodiments.

FIG. 1D is an expanded side schematic view of a module portionillustrating various features of a multilayered flap and sealed space ofa flexible photovoltaic module, in accordance with certain embodiments.

FIG. 2A is a top schematic view of a flexible photovoltaic module havingmost of the flap formed by two sealing sheets, in accordance withcertain embodiments.

FIG. 2B is a side cross-section schematic view of the flexiblephotovoltaic module in FIG. 2A illustrating various features of thejunction box and other module components, in accordance with certainembodiments.

FIG. 2C is another side cross-section schematic view of the flexiblephotovoltaic module in FIG. 2A, in accordance with certain embodiments.

FIG. 3 is an expanded side schematic view of a module portionillustrating various features of a flap and tapered edge of a junctionbox extending in between sealing sheets, in accordance with certainembodiments.

FIG. 4 is an expanded side schematic view of a module portionillustrating various features of a flap and portion of a junction boxextending over a front side sealing sheet, in accordance with certainembodiments.

FIG. 5A is a top schematic view of a flexible photovoltaic module havinga junction box for interconnecting multiple electrical leads of themodule with conductive elements, in accordance with certain embodiments.

FIG. 5B is a top schematic view of the flexible photovoltaic module withinterconnected electrical leads and conductive elements, in accordancewith certain embodiments.

FIG. 5C is an expanded view of the junction box from FIG. 5Billustrating electrical connections made between electrical leads andconductive elements of the flexible photovoltaic module, in accordancewith certain embodiments.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the presented concepts. Thepresented concepts may be practiced without some or all of thesespecific details. In other instances, well known process operations havenot been described in detail so as to not unnecessarily obscure thedescribed concepts. While some concepts will be described in conjunctionwith the specific embodiments, it will be understood that theseembodiments are not intended to be limiting.

INTRODUCTION

Flexible photovoltaic modules are made from various flexible components,such as flexible sealing sheets and flexible photovoltaic cells. Use ofthese flexible components allows these modules to bend during handlingand installation. These modules may be installed on surfaces that arenot perfectly flat and may have some vertical surface variations. Forexample, flexible modules may be installed on commercial buildingrooftops. Such rooftops are substantially horizontal but may have somesurface bumps and even small vertical steps, which are collectivelyreferred to as topographical variations.

During installation, a flexible photovoltaic module is connected toother modules and/or various electrical components of the photovoltaicarray, such as return lines, inverters, and the like. To form theseconnections, a flexible photovoltaic module may have one or moreconductive elements accessible during installation and used forconnecting to external components, such as conductive elements ofadjacent modules. Some examples of these conductive elements includeconductive portions of module connectors, electrical leads, wires, andother similar electrical components. For example, conductive elementsmay be designed to make electrical connections to standard HQRP MC4photovoltaic connectors or some other types of external photovoltaicconnectors.

One or more conductive elements of a flexible photovoltaic module may beconnected to its photovoltaic cells sealed inside the module. In thesame or other embodiments, one or more conductive elements may beconnected to return lines provided within the module that typicallyextend along or across the module. The electrical connections betweenconductive elements and photovoltaic cells or between conductiveelements and return lines may be provided by electrical leads. Theelectrical leads may extend from a junction box supporting theconductive elements and into the sealed space of the module. Theelectrical leads may extend through a sealing interface formed by bothsealing sheets and, in certain embodiments, extend through an edge seal,if one is used to form the sealing interface. Electrical leads may be inthe form of thin but sufficiently conductive metal strips, which aresometimes referred to as bus bars because of their flat aspect ratios(i.e., their height being substantially smaller than their width).

In embodiments described herein electrical leads do not interfere withthe sealing interface to maintain the integrity and sealingcharacteristics of this interface. For example, excessive stresses onthe electrical leads are avoided at least at the sealing interface.Therefore, electrical leads and/or conductive elements are adequatelysupported to prevent stresses generated during installation andoperation of the module from being transferred to the sealing interface.In some embodiments, a junction box may be used for this mechanicalsupport. A junction box can be made from rigid insulating materials andrigidly attached to other components of the module, such as its sealingsheets. Furthermore, the junction box may support one or more conductiveelements and make electrical connections to these conductive elements.In certain embodiments, a junction box is provided outside of the sealedspace. In the same or other embodiments, a junction box is positionedadjacent to the sealing interface and may even overlap and/or protectthis interface.

According to various embodiments, a flexible photovoltaic moduleincludes a flap configured to support a junction box. In certainembodiments, a flap includes only one flexible sealing sheet. Forexample, a flap may be formed by extending a back side flexible sealingsheet beyond an edge formed by the front sealing sheet. In otherembodiments, a flap includes both sealing sheets. For example, a frontsealing sheet may have a cutout that allows attaching the junction boxto the front surface of the back sealing sheet. Materials of the backsealing sheet may be configured to ensure bonding to the junction boxand support to the junction box. Specifically, a front facing surface ofthe back side sealing sheet may include at least one material configuredfor attaching to adhesives and other similar bonding components. In aspecific example, the front facing surface of the back side sealingsheet includes a non-fluorinated polymer. Unlike fluorinated polymers,non-fluorinated polymers are capable of binding with a variety ofadhesives.

In certain embodiments, a multi-layered flap is formed by one of theflexible sealing sheets and one or more additional sheets. These one ormore additional sheets are attached to a portion of the flexible sealingsheet extending past the edge separating the flap and sealed portion ofthe module. For example, a portion of the back sealing sheet may extendbeyond the front sheet edge. One or more additional sheets may bepositioned on the front facing surface of this portion of the backsealing sheet. In another example, a portion of the front sealing sheetextends past the back sheet edge. One or more additional sheets may bepositioned on the front facing surface of this portion of the frontsealing sheet, making this surface suitable for supporting a junctionbox.

Additional sheets attached to portions of one of the flexible sealingsheets may provide environmental protection, mechanical strength, and/ora surface suitable for attaching a junction box. For example, acomposite flap may be substantially stiffer than the back side flexiblesealing sheet by itself. One or more additional sheets may provide a newfront facing surface that is more compatible with adhesives used forattaching a junction box. For example, a functionalized surface may beused to provide good adhesion of the junction box.

A back side flexible sealing sheet may be made from different materialsthan the front side sealing sheet. For example, materials morecompatible for bonding with supporting surfaces (such as rooftopmembranes) may be used for back side sealing sheets. In the same orother embodiments, materials more compatible for supporting adhesivesand junction boxes are used for back side sealing sheets. Some examplesof materials suitable for back side sealing sheets includepolypropylene, including polypropylene having a high filler content,ethylene propylene diene monomer, and santoprene. Some of thesematerials are less expensive than materials typically used for frontside flexible sealing sheets, such as fluorinated polymers, and may bemore suitable for bonding to junction boxes.

Flexible Photovoltaic Module Examples

To provide some context to various flap and junction box featuresdescribed in this document, various examples of flexible photovoltaicmodules are first described. FIGS. 1A and 1B are top and side schematicviews of flexible photovoltaic module 100 having flap 104 supportingjunction box 110, in accordance with certain embodiments. Flexiblephotovoltaic module 100 also includes one or more photovoltaic cells106. Photovoltaic cells 106 are provided in sealed space 102 formed byfront side flexible sealing sheet 132 and back side flexible sealingsheet 134. An interface between sealed space 102 and flap 104 isreferred to as sealing interface. In certain embodiments, the sealinginterface coincides with an edge of one or both sealing sheets. In otherembodiments, both sealing sheets protrude past the sealing interface,and the sealing interface may coincide with an edge seal, for example.That edge seal can define the boundary of the sealed space. In theselatter embodiments, the flap can be formed at least in part by bothsealing sheets.

The boundary of sealed space 102 may be defined by an overlap of frontside flexible sealing sheet 132 and back side flexible sealing sheet134. For example, FIG. 1B illustrates front side flexible sealing sheet132 being shorter (in the X direction) than back side flexible sealingsheet 134. In this example, front side flexible sealing sheet 132 formsedge 105. At the same time, back side flexible sealing sheet 134 extendspast this edge 105. In this example, the boundary of sealed space 102may coincide with front side flexible sealing sheet 132 if front sideflexible sealing sheet 132 is sealed along its edges with respect toback side flexible sealing sheet 134. In certain embodiments, theboundary of sealed space 102 is defined by location of edge seal 136.

Flap 104 extends outside of sealed space 102 and may be attached to ormonolithic with one or both sealing sheets. In certain embodiments, theorientation of flap 104 is defined with respect to front sheet edge 105.Specifically, FIGS. 1A and 1B illustrate flap 104 extending outside ofsealed space 102 on the opposite side of front sheet edge 105 withrespect to sealed space 102. In certain embodiments, flap 104 ismonolithic with one or both sealing sheets. As shown in FIG. 1B, backside flexible sealing sheet 134 extends past front sheet edge 105 toform flap 104. In this illustrated embodiment, the portion of back sideflexible sealing sheet 134 extending past edge 105 forms the entire flap104. In other embodiments, a flap may be formed by a combination of thetwo sealing sheets, by a combination of one sealing sheet and one ormore additional sheets, or by combination of the two sealing sheets andone or more additional sheets. For purposes of these documents, anadditional sheet is defined as a sheet that is not monolithic witheither front side flexible sealing sheet 132 or back side flexiblesealing sheet 134. An additional sheet may be made from the same ordifferent materials than either one of the two sealing sheets. In yetother embodiments, a flap may be formed by one or more additional sheetswithout any portions of the two sealing sheets extending into the flaparea. For example, an additional sheet may be attached to a back sideflexible sealing sheet, to a front side flexible sealing sheet, or both.This additional sheet may extend beyond the two sealing sheets and forma flap that supports a junction box.

Flap 104 supports junction box 110. In certain embodiments, junction box110 is attached to front facing surface 111 of flap 104. For simplicity,front facing surfaces or light incident surfaces are referred to asfront surfaces. Additional support to junction box 110 may be providedby other module components that are not part of flap 104. For example,junction box 110 may be additionally attached to front side flexiblesealing sheet 132 with adhesives or sealants. In the same or otherembodiments, junction box 110 may be additionally supported by extendinga portion of junction box 110 in between the front and back sideflexible sealing sheets. For example, a tapered edge of the junction boxmay extend in between the sealing sheets. Furthermore, junction box 110may be additionally supported by extending a portion of the junction box110 over the front surface of front side flexible sealing sheet 132.

Junction box 110 is supported with respect to flap 104 or, morespecifically, with respect to edge 105 to minimize the stress exerted byleads 116 and 118 on the sealing interface. FIG. 1A illustrateselectrical leads 116 and 118 protruding from sealed space 102 and intojunction box 110 along the X direction. Junction box 110 may at leastpartially enclose and support leads 116 and 118. Furthermore, junctionbox 110 may facilitate attachment of electrical leads 116 and 118 toconductive elements 112 and 114. To avoid interference between leads 116and 118 and the sealing interface, junction box 110 is fixed withrespect to this interface. Another reference point for attachment ofjunction box may be edge 105, which, in certain embodiments, define thesealing interface.

Junction box 110 may include one or more rigid materials, such aspolyethylene terephthalate (e.g., RYNITE® available from Du Pont inWilmington, Del.), polybutylene terephthalate (e.g., CRASTIN® alsoavailable from Du Pont), nylon in any of its engineered formulations ofNylon 6 and Nylon 66, polyphenylene sulfide (e.g., RYTON® available fromChevron Phillips in The Woodlands, Tex.), polyamide (e.g., ZYTEL®available from DuPont), polycarbonate (PC), polyester (PE),polypropylene (PP), and polyvinyl chloride (PVC) and weatherableengineering thermoplastics such as polyphenylene oxide (PPO),polymethylmethacrylate (PMMA), polyphenylene (PPE),styrene-acrylonitrile (SAN), polystyrene (PS) and blends based on thosematerials. Furthermore, weatherable thermosetting polymers, such asunsaturated polyester (UP) and epoxy, may be used. Other examplesinclude engineered polymers that are specifically formulated to meetrequirements specific for photovoltaic applications. For example,certain hybrid block co-polymers may be used. These materials meetspecific requirements of photovoltaic applications, such as temperaturevariation stability, moisture stability, ultra violet (UV) stability,and the like. In specific embodiments, a junction box is made from oneor more of the following polymers: polyethylene terephthalate,polybutylene terephthalate, nylon, polyphenylene sulfide, and polyamide.

An electrical lead extending into a junction box may be connected to aconductive element supported by the junction box. FIG. 1A illustrateselectrical lead 116 being connected to conductive element 114 and,separately, electrical lead 118 being connected to conductive element112. Conductive elements 112 and 114 are configured for making externalelectrical connections, for example, to similar conductive elements ofanother module, jumper connector, inverter, and the like. Any number ofleads and conductive elements may be provided in the same junction box.For examples, FIGS. 5A-5C illustrate eight electrical leads protrudinginto a junction box and two conductive elements provided in that box.Each electrical lead may be connected to a separate conductive elementas shown in FIG. 1A. In other embodiments, one electrical lead may beconnected to multiple conductive elements. In the same or otherembodiments, one conductive element may be connected to multipleelectrical leads in the junction box as further described below withreference to FIGS. 5A-5C. These connections may be provided in thejunction box during fabrication of the photovoltaic module or providedin the field.

Electrical leads extending from a junction box may be also connected tophotovoltaic cells and/or return lines. FIG. 1A illustrates electricallead 116 connected to cells 106 or, more specifically, to the back sideof the left most cell in the set. Lead 118 is also shown connected tocells 106 but it is connected to interconnecting wire network 107positioned over the front side of the right most cell in the set. Assuch, leads 116 and 118 may have different polarities. FIG. 1Aillustrates all photovoltaic cells being interconnected and forming thesame set. In certain embodiments, photovoltaic cells may be arrangedinto multiple sub-sets. In these embodiments, a junction box may haveelectrical leads connected individually to different sub-sets ofphotovoltaic cells as further explained below with reference to FIGS. 5Aand 5B. In these embodiments, the sub-sets may be interconnected in thejunction box according to different connection schemes, e.g., inparallel or in series.

In certain embodiments, a flexible photovoltaic module may have one ormore return lines. A return line is not connected to any photovoltaiccells of the module. Instead both ends of return line may be connectedto conductive elements provided, for example, in different junctionboxes. The return line extends between these junction boxes and acrossor along the module. The return line may be connected directly to theconductive elements or through electrical leads, e.g., similar toconnections to the photovoltaic cells explained above. In the case ofdifferent connections, the return line may extend through one or moresealing interfaces. In these embodiments, a return line may berelatively wide and thin, similar to a bus bar.

Conductive elements of a junction box may be electrical wires extendingfrom the junction box, pins, sockets, and/or various other types ofconductive components for connecting to external components. In aspecific embodiment, a conductive element may be a socket for receivingand connecting to another conductive element of an adjacent photovoltaicmodule during installation. Conductive elements may be equipped withvarious safety features to prevent accidental touching of conductiveelements.

Photovoltaic cells 106 in module 100 are flexible photovoltaic cells.Examples of flexible photovoltaic cells include copper indium galliumselenide (CGCS) cells, cadmium-telluride (Cd—Te) cells, amorphoussilicon (a-Si) cells, micro-crystalline silicon (Si) cells, crystallinesilicon (c-Si) cells, gallium arsenide (GaAs) multi-junction cells,light adsorbing dye cells, organic polymer cells, and other types ofphotovoltaic cells. A photovoltaic cell typically has a photovoltaiclayer that generates a voltage when exposed to light. The photovoltaiclayer may be positioned adjacent to a back conductive layer, which, incertain embodiments, is a thin flexible layer of a metal such asmolybdenum (Mo), niobium (Nb), copper (Cu), silver (Ag), andcombinations and alloys thereof. The photovoltaic cell may also includea flexible conductive substrate, such as stainless steel foil, titaniumfoil, copper foil, aluminum foil, or beryllium foil. Another exampleincludes a conductive oxide or metallic deposition over a polymer film,such as polyirnmide. In certain embodiments, a substrate has a thicknessof between about 2 mils and 50 mils (e.g., about 10 mils), with otherthicknesses also in the scope of the embodiments described herein. Thephotovoltaic cell may also include a top flexible conductive layer. Thislayer can include one or more transparent conductive oxides (TCO), suchas zinc oxide, aluminum-doped zinc oxide (AZO), indium tin oxide (ITO),and gallium doped zinc oxide. A typical thickness of a top conductivelayer is between about 100 nanometers and 1,000 nanometers or, morespecifically, about 200 nanometers and 800 nanometers. Photovoltaiccells 106 may be interconnected, for example, by one or more wirenetworks 107. A wire network 107 may extend over a front side of onecell as well as over a back side of another adjacent cell tointerconnect these two cells in series as shown in FIGS. 1A and 1B.

Sealing sheets 132 and 134 may include flexible materials, such aspolyethylene, polyethylene terephthalate (PET), polypropylene,polybutylene, polybutylene terephthalate (PBT), PPO, polyphenylenesulfide (PPS) polystyrene, PC, ethylene-vinyl acetate (EVA),fluoropolymers (e.g., polyvinyl fluoride (PVF), polyvinylidene fluoride(PVDF), ethylene-terafluoethylene (ETFE), fluorinated ethylene-propylene(FEP), perfluoroalkoxy (PFA) and polychlorotrifluoroethane (PCTFE)),acrylics (e.g., poly(methyl methacrylate)), silicones (e.g., siliconepolyesters), and/or PVC, as well as multilayer laminates andco-extrusions of these materials. A typical thickness of a sealing sheetis between about 5 mils and 100 mils or, more specifically, betweenabout 10 mils and 50 mils, though other thicknesses may be used as well.In certain embodiments, a back side flexible sealing sheet includes ametallized layer to improve its water permeability characteristics. Forexample, a metal foil may be positioned in between two insulating layersto form a composite back side flexible sealing sheet.

In certain embodiments, back side flexible sealing sheet 134 is madefrom material that is different than a material of front side flexiblesealing sheet 132. Materials for back side flexible sealing sheet 134may be specifically selected to ensure compatibility of back sideflexible sealing sheet 134 with various supporting structures to whichthe module is attached during later fabrication and/or installation. Forexample, back side flexible sealing sheet 134 may be attached to anintermediate base sheet or directly to a rooftop membrane. Theattachment may be by direct welding, using adhesives, or some otherattachment technique. An intermediate base sheet or a rooftop membranemay be made from various materials, such as ethylene propylene dieneterpolymer (EPDM), thermoplastic olefin (TPO), PVC,styrene-butadiene-styrene (SBS) modified bitumen, atactic polypropylene(APP) modified bitumen, and polyvinyl idene fluoride (PVDF). Some ofthese materials may be used as layers or coatings provided over steel oraluminum sheets. In certain embodiments, back side flexible sealingsheet 134 may include at least a back surface made from EPDM, TPO, SBS,APP, and/or PVDF. In other embodiments, the entire back sealing sheet ismade from one or more of these materials. Other examples of materialsfor fabricating back side flexible sealing sheet 134 includepolypropyelene (such as polypropyelene with a high content of filler,e.g., at least about TBD % of filler by weight) and santoprene.

Materials for back side flexible sealing sheet 134 may be also selectedto ensure sufficient support to junction box 110. For example, back sideflexible sealing sheet 134, or at least its front side surface or, moregenerally, the surface facing junction box 110 may not containfluoro-polymers. Fluoro-polymers, such as TBD, are commonly used forfront sealing sheets because of their transparency characteristics andUV stability. However, fluoro-polymers are difficult to bond to.Furthermore, fluoro-polymers are often expensive than many othermaterials that could be used as back side sealing sheets or additionalsheets that form flap 104.

In certain embodiments, a flap portion of back side flexible sealingsheet 134 may be specifically treated to improve its surface bondingproperties. For example, the junction box facing surface may befunctionalized by impregnation with filler particles or other materialsthat bond with adhesives and other like materials. In other embodiments,further described below, back side flexible sealing sheet 134 may belaminated with other sheets in the flap area to provide bonding surfaceand, for example, mechanical strength.

In certain embodiments, back side flexible sealing sheet 134 may bethicker than front side flexible sealing sheet 132. Additional thicknesscan provide support to junction box 110 in the flap area and, forexample, facilitate bonding the back sealing sheet to other structures.Back side flexible sealing sheet 134 may be generally substantiallythinner than rooftop membranes. In certain embodiments, the thickness ofback side flexible sealing sheet 134 is less than 80 mils or, morespecifically, less than 40 mils or even less than 20 mils.

In certain embodiments, flexible photovoltaic module 100 has anencapsulant layer positioned in between front side flexible sealingsheet 132 and photovoltaic cells 106. Another encapsulant layer may beprovided between back side flexible sealing sheet 134 and photovoltaiccells 106. Examples of encapsulant layer materials include non-olefinthermoplastic polymers or TPO, such as polyethylene (e.g., a linear lowdensity polyethylene), polypropylene, polybutylene, PET, PBT,polystyrene, polycarbonates, fluoropolymers, acrylics, ionomers,silicones, and combinations thereof.

Flexible photovoltaic module 100 may also include an edge seal 136 thatsurrounds and seals photovoltaic cells 106 together with sealing sheets132 and 134 as well as with other components. Edge seal 136 may preventmoisture from penetrating towards cells 106. Edge seal 136 may be madefrom certain organic or inorganic materials that have low inherent watervapor transmission rates. In certain embodiments, edge seal 136 isconfigured to absorb moisture from inside the module in addition toprotecting the module from moisture ingression. For example, abutyl-rubber containing moisture getter or desiccant may be added toedge seal 136. In certain embodiments, a portion of the edge seal 136that contacts electrical components (e.g., bus bars) of module 100 ismade from a thermally resistant polymeric material. Edge seal 136 mayalso secure front side flexible sealing sheet 132 with respect to backside flexible sealing sheet 134. In certain embodiments, edge seal 136determines boundaries of sealed space 102. Furthermore, edge seal 136may at least partially overlap with a portion of the junction boxextending between the sealing sheets to provide additional support tothe junction box as further explained below with reference to FIG. 3.

A portion of the module between sealed space 102 and junction box 110may include various features for sealing, protecting, insulating, and/orreinforcing the sealing interface and/or to support junction box. Someof these features will now be described with reference to FIG. 1C.Specifically, FIG. 1C is an expanded side schematic view of moduleportion 120 between sealed space 102 and junction box 110, in accordancewith certain embodiments. This figure shows portions of front sideflexible sealing sheet 132 and back side flexible sealing sheet 134 aswell as one of photovoltaic cells 106 sealed in between these twosealing sheets. This photovoltaic cell is shown connected to conductiveelement 112 by electrical lead 118. Lead 118 extends through edge seal136 and front sheet edge 105 and into junction box 110. Junction box 110is separated from edge 105 by a certain distance (identified as “Gap” inFIG. 1C). To protect electrical lead 118 (and other leads) within thisgap from accidental contact with various sharp objects, module 100 mayinclude puncture resistant structure 140. This structure 140 ismechanically strong and can protect electrical lead 118 from beingpunctured by sharp objects during installation and operation of themodule. Puncture resistant structure 140 may also provide environmentalprotection, rigidity, mechanical stability, and electrical insulation toparts of the sealing interface and lead 118.

Some examples of materials for puncture resistant structure 140 includePET, polyethylene naphthalate (PEN), poly(ETFE), ionomer resins (e.g.,poly(ethylene-co-methacrylic acid)), polyamide, polyetherimide (PEI),polyetheretherketone (PEEK), and various combinations thereof. Thesematerials may be formed into and provided as a film. Puncture resistantstructure 140 may have one or more adhesive layers disposed on one orboth sides of the film, such as Surlyn®, available from E. I. du Pont deNemours and Company in Wilmington, Del. For example, a support structuremay have three polymer layers, such as a co-extruded stack containingSurlyn®, PET, and another layer of Surlyn® (with the PET layerpositioned in between the two Surlyn® layers).

Puncture resistant structure 140 may extend above electrical lead 118 atleast within the gap. In certain embodiments, a similar punctureresistant structure is positioned on the other side of lead 118, whichis shown as element 138 in FIG. 1C. Puncture resistant structure 138 mayattach lead 118 to and/or support lead 118 with respect to back sideflexible sealing sheet 134. One or both puncture resistant structures138, 140 may extend into junction box 110 and/or in between front sideflexible sealing sheet 132 and back side flexible sealing sheet 132,thereby providing rigidity to module portion 120.

FIG. 1C also illustrates sealant 142 provided in the gap betweenjunction box 110 and front sheet edge 105. Sealant 142 may extend overthe front surfaces of junction box 110 and front side flexible sealingsheet 132 as shown in the figure. Sealant 142 may prevent water fromcollecting in the gap and interfering with the performance of themodule. For example, if water is collected in the gap, freezing andthawing cycles may stress the sealing interface and potentiallycompromise the seal and performance of the module.

Examples of sealant 142 include silicone based PV 804 Neutral Sealantavailable from Dow Corning in Midland, Mich. Other examples includeionomers, acrylates, acid modified polyolefins, anhydride modifiedpolyolefins, polyimides, polyamides, and various cross-linkablethermoplastics. More specific examples include BYNEL® resins supplied byDuPont in Wilmington, Del. For example, the following may be used:Series 1100 acid-modified ethylene vinyl acetate (EVA) resins, Series2000 acid-modified ethylene acrylate polymers, Series 2100anhydride-modified ethylene acrylate copolymers, Series 3000anhydride-modified EVA copolymers, Series 3100 acid- andacrylate-modified EVA resins (which provide a higher degree of bondstrength that Series 1100 resins), Series 3800 anhydride-modified EVAcopolymers (with a higher level of vinyl acetate in the EVA componentthan the 3000 and 3900 series), Series 3900 anhydride-modified EVAresins (with an improved level of bonding to polyamides and EVOH),Series 4000 anhydride-modified high density polyethylene resins (HDPE)resins, Series 4100 anhydride-modified linear low density polyethylene(LLDPE) resins, Series 4200 anhydride-modified low density polyethylene(LDPE) resins, and Series 5000 anhydride-modified polypropylene (PP)resins. Another specific example is JET-MELT® Polyolefin BondingAdhesive 3731 supplied by 3M Engineered Adhesives Division in St. Paul,Minn. Some of these resins can be mixed with other resins or fillers,such as polypropylene and polystyrene resins, as well as variousionomers, to adjust their thermal stability, viscosity of the moltenstate during fabrication, and adhesion properties.

In certain embodiments, a material 146 can be disposed between junctionbox 110 and back side flexible sealing sheet 134. Material 146 caninclude one or more of the adhesives described above. The puncture proofstructure 138 disposed between lead 118 and back side sealing sheet canalso include such an adhesive.

Flap Examples

Flaps that support junction boxes may be formed by extending one or moresealing sheets outside of the sealed areas. These extended flap portionsof the sealing sheets may be reinforced or otherwise modified byadditional sheets. FIG. 1D illustrates a portion of flexiblephotovoltaic module 150 having multilayered flap 164, in accordance withcertain embodiments. Multilayered flap 164 may be formed by two or moresheets, such as extending back side flexible sealing sheet 154 outsideof sealed space 162 and positioning another sheet 156 over thisextension as shown in FIG. 1D. Each layer in a multilayered flap maycorrespond to a separate sheet. In certain embodiments, one or moresheets forming a multilayered flap may have multilayered structure asfurther explained below with reference to elements 154 a, 154 b, 156 aand 156 b.

Returning to FIG. 1D, sheet 156 may be referred to as a top layer ofmultilayered flap 164. Sheet 156 may extend over the entire surface ofmultilayered flap 164 or just a portion of this surface. In certainembodiments (not shown), a top layer may extend from the front sheetedge and under the junction box but not to the edge of the flap. Inother embodiments (not shown), the entire flap (multilayered orsingle-layered) may end at the junction box such that the junction boxmay be positioned at the edge of the flap.

Back side flexible sealing sheet 154 may itself be a multilayeredstructure and may include first layer 154 a and second layer 154 b. Incertain embodiments, a similar multilayered sheet may be used as a topportion in the flap area. As shown in FIG. 1D, additional sheet 156includes first layer 156 a and second layer 156 b. In certainembodiments, first layer 156 a of additional sheet 156 is the same asfirst layer 154 a of back side flexible sealing sheet 154, while secondlayer 156 b of additional sheet 156 is the same as second layer 154 b ofback side flexible sealing sheet 154. In these embodiments, multilayeredflap 164 may be formed by positioning first layer 156 a of additionalsheet 156 over first layer 154 a of back side flexible sealing sheet 154(as shown) or by positioning second layer 156 b of additional sheet 156over second layer 154 b of back side flexible sealing sheet 154 (notshown). Use of the same material in adjacent layers may help to providerstronger bonds. Sheets 154 and 156 may be laminated to each other toprovide bonding between layers 154 a and 156 a.

In certain embodiments, a flap is formed by both the front and back sideflexible sealing sheets. FIGS. 2A-2C are top and two cross-sectionalside schematic views of flexible photovoltaic module 200 having flap 204formed by front side flexible sealing sheet 232 and back side flexiblesealing sheet 234, in accordance with certain embodiments. In theseembodiments, boundaries of two sealing sheets 232 and 234 may coincideand include flap 204 as well as sealed space 202. In some embodiments,the interface between flap 204 and sealed space 202 may not have an edgeextending across the entire width of module 200. Instead, the interfacemay be defined by edge seal 236. In certain embodiments, edge seal 236may be also provided within the boundaries of flap 204 to seal the spacebetween two sheets 232 and 234 in this area as well. Edge seal 236 maybe also provided around the opening made in front side flexible sealingsheet 232 as shown in FIG. 2A.

To better illustrate various details of the module around the junctionbox, two cross-sectional views of flexible photovoltaic module 200 areprovided. FIG. 2B is a cross-sectional side schematic view of flexiblephotovoltaic module 200 that includes junction box 220 and correspondsto the cross-section plane A-A identified in FIG. 2A, in accordance withcertain embodiments. Junction box 220 is positioned within the cutoutmade in front side flexible sealing sheet 232. The cutout defines edge205 of front side flexible sealing sheet 232, which may be used forreferencing the position of junction box 220. The cutout may or may notextend to any outside edges of front side flexible sealing sheet 232; inthe embodiment shown in FIG. 2A, it does not extend to any outsideedges. The cutout allows for attaching junction box 220 to front sideflexible sealing sheet 232, similar to the embodiments described above.The interface between junction box 220 and inside edges of front sideflexible sealing sheet 232 may be sealed with various sealing materialsdescribed above.

FIG. 2C is another cross-sectional side schematic view of flexiblephotovoltaic module 200 that does not include junction box 220 in itscross-section plane B-B, also identified in FIG. 2A, in accordance withcertain embodiments. FIG. 2C is presented to illustrate variousdifferences in the two cross-sectional schematic views. As shown in thisfigure, sealing sheets 232 and 234 extend between opposites edges ofmodule 200 in the X direction.

In certain embodiments, the front light-incident surface of a flap mayhave a light reflecting material or color. This feature may reduceunwanted heating of the module in this area and protect, to a certainextent, the sealing interface adjacent to the flap. For example, a frontside of the flap may have white, silver, or some other light color. Incertain embodiments, the color of the front side of the flap may matchthe color of the rooftop membrane.

Junction Box Examples

A junction box may be used to make one or more electrical connections toelectrical leads extending from the sealed space. For example, theseleads may be interconnected with various conductive elements provided inthe junction box. Other functions of a junction box may includeprotecting and insulating the electrical leads as they extend out of thesealed space, reinforcing the interface between the sealing sheets andjunction box, and housing connectors and various electrical andelectronic components. Overlapping a portion of the junction box with atleast the front side flexible sealing sheet may provide protection andinsulation for the electrical leads as they extend out of the sealedspace. This portion may extend in between the sealing sheets as shown inFIG. 3 or over the front sealing sheet as shown in FIG. 4.

Specifically, FIG. 3 illustrates a portion of flexible photovoltaicmodule 300 having junction box 310 with tapered edge 312 extendingbetween back side flexible sealing sheet 344 and front side flexiblesealing sheet 342, in accordance with certain embodiments. Tapered edge312 may also overlap with edge seal 336. Tapered edge 312 may protrudethrough seal 336 (not shown) or its tip may be buried in the edge seal336, as shown in FIG. 3. This overlap between edge seal 336 and taperededge 312 may support junction box 310, in addition to other supportingfeatures. Any gap between junction box 310 and edge 305 may be filledwith sealant 343, which may also provide some support to junction box310 with respect to edge 305. In certain embodiments, adhesive material346 attaches a portion of junction box 310 to back side flexible sealingsheet 344. Various shapes of an edge extending in between the twosealing sheets may be used.

FIG. 4 illustrates a portion of flexible photovoltaic module 400 havingjunction box 410 extending over edge 405 of front side flexible sealingsheet 432, in accordance with certain embodiments. Specifically,junction box 410 has extension 412 extending over the front surface ofsealing sheet 432. In certain embodiments, extension 412 may be bondedor sealed to the front surface of sealing sheet 432. Junction box 410may be also attached to back side flexible sealing sheet 434 using, forexample, a patch of adhesive 436.

Junction boxes and their extending portions described above may be madefrom rigid insulating materials, various examples of which are listedabove. As such, the electrical leads may be adequately protected bythese extending portions, with no separate puncture resistant structuresused at this interface. Furthermore, the rigidity of the extensions andtheir overlap and, in certain embodiments, bonding to one or bothsealing sheets, may stiffen the interface and reduce the stresses thatelectrical leads may exert on the sealing interface.

Attachment of Flexible Photovoltaic Modules to Rooftop Membranes

Flexible photovoltaic modules may be used on rooftops of variousbuildings that are protected from the environment by rooftop membranes.The modules may be secured directly to such membranes without a need forspecific mounting hardware. In certain embodiments, intermediate basesheets may be used to integrate multiple modules into the same assemblyand to provide additional protection to the building after installationof the module. Attachments between back side flexible sealing sheets,rooftop membrane sheets, and intermediate base sheets, if used, may beperformed by the welding of two or more sheets that are made compatiblematerials, by applying an adhesive in between adjacent sheets, and othersimilar methods.

In certain embodiments, a flexible photovoltaic module may include anadhesive positioned on the back side flexible sealing sheet or, morespecifically, on the back surface (i.e., the external side with respectto the photovoltaic cells) of the back side flexible sealing sheet. Thisadhesive may be used during installation to attach modules to a rooftopmembrane or some intermediate structure. Some examples of adhesivesinclude hot mop asphalt, pine tar pitches, ethylene vinyl acetate,polyurethane (e.g., moisture cured silinated polyurethane, siliconeepoxy, styrene-isoprene-styrene, styrene-butadiene-styrenes, ethyleneethyl acrylates, butyl or halo-butyl rubbers, acrylics, ethylenepropylene rubbers, ethylene propylene diene monomers rubbers,styrene/butadiene rubbers, and styrene-ethylene-butene-styrenecopolymers. A specific example includes a pressure sensitive hot meltadhesive PSA-3 Hot Melt Adhesive, available from ADCO Products, Inc. inMichigan Center, Mich. Some of these materials may become tacky whenexposed to the higher temperature occurring during installation to formbonds with roofing membranes and other materials. To protect an adhesiveduring handling, a release liner may be provided over the adhesive.

In certain embodiments, a flexible photovoltaic module includes a basesheet attached to the back side of the back side flexible sealing sheet.The base sheet may extend outside of the boundaries of the back sideflexible sealing sheet to form extensions. These extensions may be usedto attach the module to a roofing membrane. For example, extensions maybe glued or welded to the roofing membrane.

A base sheet may be made from one or more materials compatible orsimilar to materials of the rooftop membrane. Examples include EPDM,TPO, PVC, SBS, APP, and PVDF. The thickness of the base sheet isgenerally greater relative to the thickness of the back side flexiblesealing sheet. In certain embodiments, the thickness of the base sheetis substantially the same as the thickness of the roofing membrane.Specifically, the thickness may be at least about 40 mils or, morespecifically, at least about 80 mils.

A base sheet may provide additional protection to the roofing structurepositioned on the other side of the roofing membrane. Specifically, theroofing membrane may operate at temperatures of less than 50° C.-60° C.Installing a flexible photovoltaic module made from generally lightabsorbing materials may raise this operating temperature substantially.The multilayered protection provided by a combination of the roofingmembrane and base sheet may allow the entire assembly to operate at muchhigh temperature without comprising the overall seal.

Furthermore, a base sheet may allow removing the photovoltaic membranefrom the rooftop. The base sheet may have flaps extending beyond thephotovoltaic modules. The width of such flaps may be at least about 1inch or, more specifically, at least about 2 inches, or even at leastabout 5 inches. These flaps may be used for attaching the entireassembly to the rooftop. To remove the assembly, a flap may be cut inbetween the module and attachment location. The remaining flap may belater used for attaching to another rooftop.

In certain embodiments, one base sheet may include multiple flexiblephotovoltaic modules attached to the sheet prior to installation of thisassembly onto the rooftop. The number of modules on one sheet depends onthe size of the individual modules. It is generally desirable to limitthe overall size of the assembly to one that can be handled by one ortwo installers. For example, two flexible modules that are each 1.5meter long and 1.0 meter wide may be provided in the same base sheet.

Electrical Safety and Configuration Features

When photovoltaic cells of a module are exposed to light, these cellsmay apply voltage to various conductive components of the module. Thismay occur prior to or during installation of the module. If conductiveelements of a module are connected to the cells, it may present somesafety concerns. To address these concerns, conductive elements may beenclosed in insulating bodies that prevent accidental contact but stillallow for establishing electrical connections with other conductiveelements. However, such insulating bodies may result in very thickjunction boxes (in the Z direction as shown in FIG. 1B). Excessivethickness of the connector bodies may cause tripping hazards whenrooftops are used as walkways and/or difficulties with sealing adjacentmodules.

In certain embodiments, one or more conductive elements of a flexiblephotovoltaic module are disconnected from the photovoltaic cells of thismodule prior to installation and during initial installation operations(e.g., until conductive elements are connected to other electricalcomponents and cannot be reached by installers). At some point duringinstallation, these conductive elements are connected to thephotovoltaic cells to provide a fully operational module. These laterconnections may be established in the junction box, which may beaccessible after the module is physically installed on the roof top(e.g., accessible from the front side of the module), and/or byproviding an electronic control unit that may activate this connectionafter receiving some signal. In certain embodiments, the electroniccontrol unit may be provided in the junction box.

FIG. 5A is a schematic view of flexible photovoltaic module 500including junction box 516 supported by flap 502, in accordance withcertain embodiments. Electrical leads 504 a-504 d and 505 a-505 d areconnected to respective photovoltaic cells 506 a-505 d but aredisconnected from conductive elements 512 and 514 in the state shown inFIG. 5A.

Specifically, flexible photovoltaic module 500 includes four sets ofphotovoltaic cells 506 a-506 d with each having a pair of electricalleads (i.e., set 506 a has electrical leads 504 a and 505 a, set 506 bhas electrical leads 504 b and 505 b, set 506 c has electrical leads 504c and 505 c, and set 506 d has electrical leads 504 d and 505 d).Electrical leads 504 a-504 d have a different polarity with respect toelectrical leads 505 a-505 d. Photovoltaic cells are interconnected inseries in each set. One having ordinary skill in the art wouldunderstand that other cell arrangements with flexible modules arepossible. For example, photovoltaic cells may be interconnected inparallel in each other.

Flexible photovoltaic module 500 may be manufactured in the state shownin FIG. 5A. Further, module 500 may be kept in that state untilinstallation and even during some initial installation operations. Assuch, even if the photovoltaic cells of sets 506 a-506 d are exposed tolight during handling and installation of photovoltaic module 500, thevoltage will not be applied to conductive elements 512 and 514. Incertain embodiments, photovoltaic cell electrical leads 504 a-504 d and505 a-505 d are interconnected with each other during manufacturing butare still disconnected from conductive elements 512 and 514.

FIG. 5B is a schematic view of flexible photovoltaic module 500 withelectrical leads 504 a-504 d and 505 a-505 d connected to conductiveelements 512 and 514, in accordance with certain embodiments. Junctionbox 516 may be accessed to install various bridging connectors, whichwill now be explained with reference to FIG. 5C, which illustrates anexpanded view of junction box 516 after connections have been completed.Electrical leads 504 a-504 d are interconnected with bridging connectors514 b-514 d. Electrical leads 505 a-505 d are separately interconnectedwith bridging connectors 515 b-515 d. In this embodiment, photovoltaiccell sets 506 a-506 d are interconnected in series. However, otherconnection schemes are possible as well. Interconnected electrical leads504 a-504 d are also connected to conductive element 512 using bridgingconnector 514 a. In a similar manner, interconnected electrical leads505 a-505 d are connected to conductive element 514 using bridgingconnector 515 a.

In certain embodiments, multiple bridging connectors are integrated intoa single physical component, which, for example, may be plugged into asocket provided in the junction box during one of the installationoperations. In certain embodiments, one or more bridging connectors maybe provided in junction box 516 during module fabrication. However,these bridging connectors do not make electrical connections betweenelectrical leads 504 a-504 d and conductive element 512 or betweenelectrical leads 505 a-505 d and conductive element 514. Duringinstallation, these bridging connectors are reoriented to providenecessary connections.

Prior to forming the electrical connections shown in FIGS. 5B and 5C,conductive elements 512 and 514 may be connected to other conductiveelements, such as conductive elements of another module or conductiveelements of a jumper connector. For purposes of this document, a jumperconnector is defined as a component that electrically interconnects twoor more conductive elements of the same junction box. For example,multiple flexible photovoltaic modules may be interconnected in series,forming a string of interconnected modules. Two modules in this stringrepresent end modules and are connected to only one other module in thestring. All other modules are connected to two other (e.g., adjacent)modules in the string. One end module may be connected to an inverter orsome other electrical component of the array. Another end module mayhave its return line interconnected with photovoltaic cells at its endthat is not connected to another module. Sometimes this interconnectionis performed by attaching a jumper to this end or, more specifically, toconductive elements provided at this free end. In other embodiments,this interconnection can be made within junction box 516 (for example,by interconnecting leads 514 d and 515 d). In this example, conductiveelements 512 and 514 remain unconnected to external conductive elements.

In certain embodiments, a flexible photovoltaic module includes anelectronic control unit configured to establish an electrical connectionbetween a conductive element and one or more photovoltaic cells at somepoint during installation. For example, the control unit may keep theconductive element disconnected from the one or more photovoltaic cellsuntil a predetermined signal is received during installation. Once thesignal is received, the connection is provided. The signal may besupplied wirelessly or through already established electricalconnections in the module. The electrical connections established by theelectronic control unit may be similar to the ones described above withreference to FIGS. 5A-5C.

Flexible photovoltaic module 500 may also include bypass diodes,inverters, DC/DC converters, and/or various combinations of thesecomponents (not shown in FIGS. 5A-5C). A typical bypass diode isconfigured to prevent an electrical current from flowing back into thecells that are connected to the diode but are not generating electricalpower, for example, due to shading, cell failure, and other reasons. Anelectrical resistance of the shaded cells is greater than that of thebypass diode, and the electrical current is passed (“shunted”) throughthe diode instead of passing through the cells, which could damage thecells in certain situations. Each photovoltaic cell may have a dedicatedbypass diode or a group of cells may share one diode.

Furthermore, one or more DC/DC converters may be integrated into module500. A DC/DC converter may be associated with one photovoltaic module ora set of modules. The DC/DC converter converts an input DC voltage intoa higher or lower DC voltage level required by, for example, a centralinverter. The central inverter may also be a part of the module and beconnected to a grid or other AC electrical systems. For example, severalDC/DC converters can be connected to the central inverter by conductiveelements described above. The DC/DC converters allow each module (oreach set of modules) to operate at its optimum current/voltage regime.The DC/DC converter may operate in a “buck” or “boost” mode, asappropriate. In certain embodiments, a module includes a buck converterconnected to a boost converter.

CONCLUSION

Although the foregoing concepts have been described in some detail forpurposes of clarity of understanding, it will be apparent that certainchanges and modifications may be practiced within the scope of theappended claims. It should be noted that there are many alternative waysof implementing the processes, systems, and apparatuses. Accordingly,the present embodiments are to be considered as illustrative and notrestrictive.

1. A flexible photovoltaic module comprising: a front side flexiblesealing sheet having a front sheet edge; a back side flexible sealingsheet; a sealed space formed between the front side flexible sealingsheet and the back side flexible sealing sheet, and bounded at least inpart by an edge seal; one or more flexible photovoltaic cells positionedin the sealed space between the front side flexible sealing sheet andthe back side flexible sealing sheet; a first electrical leadelectrically connected to the one or more flexible photovoltaic cells,positioned in the sealed space, and extending outside of the sealedspace and through the edge seal; a first conductive element positionedoutside the sealed space and electrically connected to the firstelectrical lead; and a housing that includes a first extension and asecond extension, and that encloses the electrical connection betweenthe first electrical lead and the first conductive element, encloses atleast a part of the first electrical lead, and encloses at least a partof the first conductive element, wherein: the first extension extendsover a portion of the front side flexible sealing sheet, the secondextension extends over a portion of the back side flexible sealingsheet, and the housing is connected to one of the front side flexiblesealing sheet or the back side flexible sealing sheet.
 2. The flexiblephotovoltaic module of claim 1, wherein a portion of the housing extendsthrough the edge seal.
 3. The flexible photovoltaic module of claim 1,further comprising: a second electrical lead electrically connected tothe one or more flexible photovoltaic cells, positioned in the sealedspace, and extending outside of the sealed space and through the edgeseal; and a second conductive element positioned outside the sealedspace and electrically connected to the second electrical lead, whereinthe housing further encloses the electrical connection between thesecond electrical lead and the second conductive element, at least apart of the second electrical lead, and at least a part of the secondconductive element.
 4. The flexible photovoltaic module of claim 3,wherein the first electrical lead has an opposite polarity of the secondelectrical lead.
 5. The flexible photovoltaic module of claim 1, whereinat least a section of the housing is comprised of a rigid material. 6.The flexible photovoltaic module of claim 1, wherein the housing ispositioned away from the edge seal by a gap.
 7. The flexiblephotovoltaic module of claim 1, wherein: the first extension contactsthe front side flexible sealing sheet, and the second extension contactsthe back side flexible sealing sheet.
 8. The flexible photovoltaicmodule of claim 1, wherein: the first extension is attached to the frontside flexible sealing sheet, and the second extension is attached to theback side flexible sealing sheet.
 9. The flexible photovoltaic module ofclaim 1, wherein the housing extends around a portion of the edge seal.10. A flexible photovoltaic module comprising: a front side flexiblesealing sheet having a front sheet edge; a back side flexible sealingsheet; a sealed space formed between the front side flexible sealingsheet and the back side flexible sealing sheet, and bounded at least inpart by an edge seal; one or more flexible photovoltaic cells positionedin the sealed space between the front side flexible sealing sheet andthe back side flexible sealing sheet; a housing positioned outside thesealed space and including a first portion that extends at leastpartially into the edge seal; and an electrical lead that is positionedat least partially in the sealed space, electrically connected to theone or more flexible photovoltaic cells, and that extends into the firstportion of the housing.
 11. The flexible photovoltaic module of claim10, wherein the first portion of the housing is tapered.
 12. Theflexible photovoltaic module of claim 10, wherein the first portion ofthe housing extends only partially into the edge seal.
 13. The flexiblephotovoltaic module of claim 10, wherein the first portion of thehousing extends through the edge seal.
 14. The flexible photovoltaicmodule of claim 10, wherein: the housing further comprises a body, thefirst portion extends away from the body, and the body directly contactsthe edge seal.
 15. The flexible photovoltaic module of claim 10,wherein: the housing further comprises a body, the first portion extendsaway from the body, and the body is offset from the edge seal by a gap.16. The flexible photovoltaic module of claim 15, further comprising asealant positioned in the gap between the body of the housing and theedge seal.
 17. The flexible photovoltaic module of claim 10, furthercomprising a flap outside the sealed space, wherein: the front sideflexible sealing sheet has a front sheet edge, the flap extends awayfrom the sealed space in a direction perpendicular to the front sheetedge and the edge seal, and the housing is attached to the flap.
 18. Theflexible photovoltaic module of claim 17, wherein the back side flexiblesealing sheet comprises the flap.
 19. The flexible photovoltaic moduleof claim 17, wherein the flap comprises two or more layers.
 20. Theflexible photovoltaic module of claim 10, further comprising an externalelectrical connector that extends into the housing and is electricallyconnected to the electrical lead inside the housing.